Box strapping apparatus



4 Sheets-Sheet 1 Filed June 24, 1955 INVENTORS. Marc/zandfi flal BYCZZz/L'n/L. win/Her Sept. 30, 1958 M. B. HALL El'AL BOX STRAPPINGAPPARATUS 4 Sheets-sheet 2 Filed June 24, 1955 Sept. 30, 1958 M. B. HALL ETAL 2,85

BOX smppmc APPARATUS Filed June 24, 1955 4 Sheets-Sheet s aad L1INVENTORS,

Marc/zandflfial rew/mi. ZZ/L'nkler Sept. 30, 1958 v i 'M. B. HALL ETAL2,853,938

BOX STRAPPING APPARATUS Filed June 24, 1955 ,4 Sheets-Sheet 4 UnitedStates Patent BOX STRAPPING APPARATUS Marchand B. Hall and Alvin L.Winkler, Chicago, 11L,

assignors to Acme Steel Company, Chicago, 11]., a corporation ofIllinois Application June 24, 1955, Serial No. 517,768

4 Claims. (Cl. 100-26) This invention relates to improvements in boxstrapping apparatus and its purpose is to provide a novel device bywhich a binding strap is guided about a box or other object to be boundpreliminary to drawing the strap taut around the object and thensecuring its ends together.

In the binding of boxes, packages and the like, it is common practice toencircle the box with a binding strap by, a manual operation without theuse of any guiding means. This method is rather slow and it isparticularly unsatisfactory when large boxes or packages are being boundsince it is then extremely difiicult for a single operator to cause thestrap to form a loop encircling the package. In many binding operations,it has been necessary to use a second operator stationed behind thepackage to assist in directing the free end of the strap over thepackage to the first operator who has passed the strap rearwardlybeneath the package. The problem is much the same whether the strap isfinally drawn taut and its ends secured together by a manual operationor by the use of a power driven machine.

It is, therefore, the principal object of the present invention toprovide improved apparatus by. which the binding strap is guided aboutthe package during the binding operation which may be performed manuallyor by a power driven machine. A further object of the invention is toprovide a novel device by which a binding strap, fed thereto manually orby power operated means, is caused to encircle the package eitherpartially or wholly. Another object of the invention is to provideapparatus comprising a guide or track adapted to direct a binding strapto form a loop around a package and then to release the strap when it isdrawn taut to cause the loop. to contract and tightly engage thepackage. Still anoher object of the invention is to provide strapguiding means adapted to extend partially or wholly about a package andcomprising resilient members adapted to retain the strap while it isbeing fed through said guiding means to encircle the package and to re-.

lease the strap automatically when the loop of strap is then drawn tautto engage the package. Other objects relate to various features ofconstruction and arrangement which will appear more fully hereinafter.

The nature of the invention will be understood from the followingspecification taken with the accompanying drawings in which oneembodiment of the invention and a modification thereof are illustrated.In the drawings,

Figure 1 shows a perspective view of a box which has been reinforced bya surrounding binding strap with the use of the apparatus of the presentinvention;

Fig. 2 shows an enlarged plan view of the welded joint by which the endsof the binding strap shown in Fig. l are united;

Fig. 3 shows a somewhat diagrammatic vertical cross section takenthrough a machine embodying the present invention illustrating the meansfor guiding the strap when it is caused to encircle the box andillustrating the relative positions of the parts at the conclusion ofthe box encircling operation;

P a-tented Sept. so, 1958 Fig. 4 shows a view similar to that of Fig. 3at a later stage of the operation when the strap has been withdrawn fromthe guiding means and contracted about the box;

Fig. 5is a view similar to those of Figs.'3 and 4 illustrating therelative positions of the parts when the box encircling portion of thestrap has been cut oil from the supply and a joint has been formedbetween the overlapping ends of that portion of the strap;

Fig. 6 shows an enlarged end elevation of and partial transversevertical section through the upper portion of the machine which isillustrated diagrammatically in Figs. 3, 4 and 5;

Fig. 7 is a partial end elevation similar to that of Fig. 6 showing amodified form of the present invention which is adapted to be used whenthe operation of extending the binding strap around the box is performedmanually;

Fig. 8 shows a top plan view of the apparatus illustrated in Fig. 6;

Fig. 9 shows an enlarged vertical section taken on the line 9-9 of Fig.6;

Fig. 10 shows a partial bottom plan view of the guide channel or trackwhich is embodied in the apparatus shown in Fig. 6 for guiding the straparound the box, a portion of the strap retaining means being shown insection;

Fig. 11 shows a bottom plan view of the strap retaining means embodiedin the guide channel shown in Fig. 10 when removed from the other partsof the structure;

Fig. 12 shows a side elevation of the strap retaining means shown inFig. 11;

Fig. 13 shows an end elevation of the strap retaining means shown inFig. 12;

, Fig. 14 shows a side elevation of the strap retaining means shown inFigs. 11 and l2when it is partially bent to pass around a curved portionof the guide channel;

there is shown a perspective view of a box 20 surrounded by a metalstrap 21 which is drawn taut around the box and which has itsoverlapping ends joined together by means of spot welds 22 as shownparticularly in Fig. 2. Other means for joining the ends of the strapmay be employed if desired.

In Figs. 3, 4, 5, 6 and 8 to 15, inclusive, of the drawings, theinvention is illustrated as being embodied in a machine which is poweroperated for the purpose of feeding the strap around the box and drawingit taut. Referring to Fig. 6, it will be seen that this inventioncomprises a table 23 upon which there is mounted a guide channel ortrack 24 having a substantially elliptical form and comprising a pair ofparallel side plates 25 which are spaced apart and provided withopenings 25a having a general rectangular form to receive thebox 20. Atthe rear of the machine, the side plates 25 are provided at their lowerextremities with outwardly extending horizontal flanges 25b which aresecured to the top of the table 23 by screws 26 and, at the forward sideof the machine, these side plates 25 are provided with other laterallyextending horizontal flanges 25c which are secured to the table top byscrews 27. The table top is provided with an opening 23a above wihch thebox 20 is adapted to be mounted for binding purposes and, in thisopening, there is mounted the mechanism by which the strap is fedthrough the guide channel 24 and thereafter drawn taut, its supplyportion cut off, and its ends joined by spot welding or the like.

As shown particularly in Figs. 8, 9 and 10, the side plates 25 of the.guide channel are secured by studs 28 to a series of blocks 29 whichare spaced apart about the guide channel and which serve not only toconnect the side plates 25 but also to" support a bar 30 ofrectangular'cross section which is bent into a substantially elliptic form tocorrespond to the general contour of the guide channel. This bar 36issecuredto the blocks 29 by a series of bolts or studs 31 and. the barserves as the bottom wall of the channel in which the metal strap 21 isadapted to travel; The metal strap is normally retained in its positionadjacent the bar 30 by means of a channel-shaped retaining member 33which has a back wall 33a clamped betwen the bar 30 and the blocks 25*and secured to the bar by a series of screws 34.

The retaining member 33 is provided on opposite sides with inwardlyextending resilient tongues 33b which terminate in inwardly inclineddownwardly converging portions 330. The tongues 33b are bent slightlyalong diagonal lines 33d '50 that adjacent tongues are relativelyinclined and are thus permitted to overlap when the retaining memberis'bent into curved form'as shown particularly in Fig. 14. The bendsalong diagonal lines 33:! also provide a modified funnel arrangement toprevent the strap leading end from snagging on the tongues 33b as it isfed through the guide track; The strap movement must be in the directionof the arrow as shown in Fig. to prevent the movement of the strap frombeing snagged by the tongues 33b. The retaining members 33 may be formedfrom a blank of thin sheet metal 33e, shown in Fig. 15, which is slottedtransversely to form a plurality of parallel arms 33 adapted to be bentinto the form of the tongues 33b. The extremities 330 of the tonguesoverlap the strap 21 when the strap is in position in the guide channelbut when the strap is contracted to move into engagement with the box20, the tongues are adapted to spring outwardly to the positions shownby dotted lines in Fig. 9 so that the strap 21 may move inwardly to theposition shown by dotted lines. The guide channel or track 24 is adaptedto extend completely around the position to be occupied by the box 20and its extremities terminate in proximity to the margins of the opening23a in the table over which the box 20 is adapted to be locatedpreliminary to the application of the binding strap.

The binding strap 21 is adapted to be drawn from a source of supply, notshown, by a power driven feed roll 35 and it is held in contact withthat feed roll by an idler roll 36. As the roll 35 rotates in thedirection of the arrow 37, the strap 21 is projected through the guidepassage 38a of the forward gripping dog 38 which is pivoted at 39 on theframe of the machine beneath the tablev The strap then extends through apassage 40a (see Fig. 3) of a guide member 40 which is located beneaththe middle portion of the box 20 and it then passes above the reargripping dog 41 and enters the guide channel of the guideway or track24. As the rotation of the feed roll 35 continues, the strap 21 ispushed around the guideway 24 in contact with the inner face of the bar30 until it emerges from the guide channel 24 and passes above theforward gripping dog 38 after which it enters a socket 40b of the guidemember 40, the movement of the strap being terminated by the engagementthereof with the end wall of this socket. The conditions are thensubstantially as shown in Fig. 3 with the binding'strap 21 retained bythe guide or track 24.

At this point, the forward gripping dog 38 is moved upwardly to grip thefree end of the strap against a stationary gripping plate 42 so thatthis end of the strap is then held in stationary position. The feedwheel 35 is then reversed in its direction of rotation so that the loopof strap extending around the box 20 is contracted and the strap movesinwardly as permitted by the flexible tongues 33b of the retainingmember 33. This movement continues until the strap is in close contactwith the surfaces of the box 20. When all of the slack has been takenout of the loop of strap by the reverse operation of the feed roll 35, apair of gripping dogs 43 are caused to grip the strap beneath the roll35 and to be moved bodily downward to tighten the strap further until apredetermined condition of tautness has been brought about. When thiscondition is reached, the rear gripping dog 41 is moved upwardly aboutits pivot 44 until the supply portion of the strap is gripped against astationary gripping plate 45. A pair of shearing blades 46 are thenoperated to sever the supply portion of the strap adjacent to the innerend of the forward gripping dog 38, thus leaving the portion of thestrap which encircles the box with two overlapping ends. These ends arethen secured together by the spot Welds 22 which are effected by themovement of an electrically actuated welding head 47 upwardly from theposition shown in Fig. 4, to the position shown in Fig. 5 where itpresses the overlapping strap ends against the welding points '48,thereby welding the strap ends together at the spaced points 22. Whenthe welding operation has been completed the welding head 47 isretracted and the other parts are restored to their initial positions inreadiness for a new binding operation. Due to the use of a large numberof retaining fingers 33b which are closely spaced, very thin metal maybe used for these fingers and the strap is progressively released as itis tightened.

The forward gripping dog 38 is adapted to be actuated by a link 50having a coil spring 51 connected there-in and having its lowerextremity connected at 52 to a bell crank lever 53. Similarly, the 'reargripping dog 41 is actuated by a link 54 having a coil spring 55connected therein and having its lower extremity connected at 56 to abell crank lever 57. The feed roll 35 and the bell crank levers 53 and57, as well as the welding head 47, are adapted to be actuated by asuitable mechanism, including rotary camsso that the successivemovements of these parts take place in the proper timed relation as thebinding of the box proceeds. A box strapping machine of this type isdescribed and claimed in the copending application of Albert L. Winkler,Robert E. Hager and Kjell A. Falck-Pedersen, Serial No. 284,634, filedApril 26, 1952.

While the apparatus of the present invention including the strap guidingchannel or track may be employed with particular advantage in poweroperated machines, particularly those adapted for the binding of largeboxes or the like, it may also be employed in binding'operations whichare carried on manually and, in Fig. 7, there is shown a modified formof apparatus which may be used for this purpose. As there shown, themachine comprises a guide channel 60 having side plates 61 which aresecured to the table in the manner previously described and this guidechannel extends forwardly over the position to be occupied by the box 62to be-bound. This guide channel terminates, however, short of theforward'edge of the table so that it is possible to insert the box 62from the forward side of the table and the strap 63 is thrust upwardlythrough the guide channel from a position beneath the box 62 until itemerges from the extremity 60a of the guide channel, whereupon this freeextremity is seized by the operator and the strap is then pulled throughthe guide channel and passed around the box until the ends of the strapoverlap. The strap may then be released manually from the fingers 33b ofthe guide channel'and then drawn taut around the box by the use of theusual strap stretching tools. When the strap has been drawn taut itsends may be secured together by a strap sealing device or other meansadapted to form an interlocking connection between the strap ends orother suitable form of joint. If desired, the complete annular guideshown in Fig. 6 could be used withamanual strapping operation. 7

Although one form of the invention and a modification of a portionthereof have been shown and described by way of illustration, it will beunderstood that it may be constructed in various other embodiments whichcome within the scope of the appended claims.

We claim:

1. The combination in box strapping apparatus, of means for supporting abox, and an arcuate guide channel through which a strap may be fedendwise around said box, said guide channel having strap retaining meanscomprising resilient fingers extending radially inwardly past theopposite edges of the strap and terminating in parts overlapping saidstrap on its inner side.

2. The combination in box strapping apparatus, of means for supporting abox, an arcuate guide channel through which a strap may be fed endwisearound said box, said guide channel having strap retaining meanscomprising resilient fingers extending radially inwardly past theopposite edges of the strap and terminating in parts overlapping saidstrap on its inner side, and means for contracting said strap intoengagement with said box,

said fingers being adapted to release said strap when it 6 the oppositeedges of said strap and terminating in flanges overlapping said strap onits inner side, said fingers being bent diagonally between their endswhereby said flanges of adjacent fingers overlap each other.

4. The combination in box strapping apparatus, of means for supporting abox, and a curved guide channel extending around at least a part of thebox for receiving a strap fed endwise therethrough, said guide channelcomprising resilient fingers on opposite sides of the channel extendinginwardly past the opposite edges of the strap and terminating in flangesoverlapping said strap on its inner side, each of said flanges beingdisposed at an angle with respect to the longitudinal direction of themovement of said strap so as to prevent the leading end of said strapfrom catching on the edges of said flanges when said strap is fedthrough said guide channel.

References Cited in the file of this patent UNITED STATES PATENTS1,650,843 McChesney Nov. 29, 1927 2,356,904 Workman Aug. 29, 19442,409,652 Workman Oct. 22, 1946 2,597,675 Sackett May 20, 1952 2,707,429Leslie et a1 May 3, 1955

